scholarly journals Determination of Seismic Wave Attenuation for the Garhwal Himalayas, India

2017 ◽  
Author(s):  
Soham Banerjee
Keyword(s):  
Seismic Wave ◽  
Wave Attenuation ◽  
Seismic Wave Attenuation ◽  
Garhwal Himalayas

DETERMINATION OF SEISMIC WAVE ATTENUATION IN ROCKS SURROUNDING UNDERGROUND EXCAVATIONS

2018 ◽  
Vol 1 ◽  
pp. 110-116
Author(s):  
V.V. Romanov ◽  
◽  
K.S. Malskiy ◽  
A.I. Poserenin ◽  
A.N. Dronov ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Wave Attenuation ◽  
Underground Excavations ◽  
Seismic Wave Attenuation

scholarly journals Forced oscillation measurements of seismic wave attenuation and stiffness moduli dispersion in glycerine‐saturated Berea sandstone

2018 ◽  
Vol 67 (4) ◽  
pp. 956-968 ◽  
Author(s):  
Samuel Chapman ◽  
Jan V. M. Borgomano ◽  
Hanjun Yin ◽  
Jerome Fortin ◽  
Beatriz Quintal
Keyword(s):  
Seismic Wave ◽  
Wave Attenuation ◽  
Forced Oscillation ◽  
Berea Sandstone ◽  
Seismic Wave Attenuation

scholarly journals ACOUSTIC SEISMIC WAVE ATTENUATION IN ROCKS: ESTIMATES INSTABILITIES, FREQUENCY-DEPENDENCE AND INCOHERENCES

2017 ◽  
Vol 35 (3) ◽  
Author(s):  
Julián David Peláez ◽  
Luis Alfredo Montes
Keyword(s):  
Frequency Shift ◽  
Seismic Wave ◽  
Wave Attenuation ◽  
Spectral Ratio ◽  
Well Logs ◽  
Well Log ◽  
Seismic Profiles ◽  
Seismic Wave Attenuation ◽  
Transmission Coefficients ◽  
Centroid Frequency

ABSTRACT. Seismic wave attenuation (Q−1) values indicate relevant media properties, such as fluid content and porosity. Q−1 estimates, obtained using both VSP and conventional well log data, did not exhibit comparable trends, nor values. Whereas VSP results represent total attenuation, well log Q−1, which, theoretically, should represent scattering losses, displayed a low percentage correlation with transmission coefficients and other well logs. The influence of processing routines, chosen methodology and input parameters on Q−1-values suggests that ASR (Amplitude Spectral Ratio) and CFS (Centroid Frequency Shift) attenuation estimates should be regarded, in practical terms, as relative quantities instead of absolute ones. Seemingly incoherent negative values are frequent, nonetheless these could hold a physical meaning related to elastic amplification at interfaces. Considering that quality factor (Q) values obtained were more unstable than Q−1-values, it is advisable to report the latter. Keywords: Vertical Seismic Profiles, well logs, transmission coefficients, scattering, amplification.RESUMO. Os valores de atenuação da onda sísmica (Q−1) indicam propriedades relavantes dos meios, tais como conteúdo de fluido e porosidade. As estimativas do Q−1, obtidas usando dados de VSP e dados de poços convencionais, não apresentaram tendências nem valores comparáveis. Enquanto os resultados de VSP representamatenuação total, os resultados dos dados de poços, que teoricamente deveriam representar perdas de dispersão, apresentaramuma baixa correlação percentual com os coeficientes de transmissão e outros dados de poços. A influência das rotinas de processamento, da metodologia escolhida e dos parâmetros de entrada nos valores Q−1 sugere que as estimativas de atenuação ASR (Amplitude Spectral Ratio) e CFS (Centroid Frequency Shift) devem ser, em termos práticos, consideradas como quantidades relativas em vez de absolutas. Valores negativos aparentemente incoerentes são frequentes, no entanto estes poderiam conter um significado físico relacionado `a amplificação elástica nas interfaces. Considerando que os valores do fator de qualidade (Q) obtidos foram mais instáveis do que os valores de Q−1, é aconselhável documentar o último. Palavras-chave: Perfis Sísmicos Verticais, registros de poços, coeficientes de transmissão, dispersão, amplificação.

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